The mission of the tissue core lab is to produce surgical manipulations of the rabbit urinary bladder in the most consistent and reproducible manner possible, and make these tissues available to participating investigators within the program project. There is a variable degree of hypertrophy noted following partial outlet obstruction even with the same surgeon and a highly standardized technique. We have correlated the degree of hypertrophy induced with non-invasively determined voiding pattern analysis. One practical application of this method is in selecting similar cohorts of rabbit bladders to undergo reversal of the outlet obstruction. Another practical application of this phenotypic classification scheme is that it enables comparison of results among the different labs within the program project each of which will get different bladders. We have also developed a means of studying murine bladder function in vivo and in vitro, and have a method of creating partial bladder outlet obstruction in male mice. The aims of the Bladder Tissue Core (Core B) are: a) Perform obstruction and reversal surgery in rabbits and mice, b) Analyze bladder functions and provide detrusor tissue samples from rabbits that show normal bladder functions and from those in which bladder functions do not return to normal, and c) Produce obstruction in normal and SM-B knockout mice, analyze their bladder function in vitro and in vivo, and provide detrusor tissues for studies of normal and severely dysfunctional bladders to investigators requiring mouse detrusor tissue (e.g. Project 3). The Core lab has recently developed the means to create partial bladder outlet obstruction in male mice and will provide project investigators with obstructed mouse bladders from normal or knockout mice (as needed by the projects). In addition, bladder tissue core will be responsible for obtaining human bladder tissue from surgical biopsies for investigators whenever available and needed.